Schema:
state (state_name, population, area, country_name, capital, density)
city (city_name, population, country_name, state_name)
border_info (state_name, border)
highlow (state_name, highest_elevation, lowest_point, highest_point, lowest_elevation)
lake (lake_name, area, country_name, state_name)
mountain (mountain_name, mountain_altitude, country_name, state_name)
river (river_name, length, country_name, traverse)
Please answer with SQL.